Oil burner



Aug. 30, 1927.

0 IL BURNER Original Filed Feb. 25, 1922 2 Sheets-Sheet 1 all/2 A. mN Nbtl | L. scoTT OIL BURNER Original Filed Feb. 23. 1922 2 Sheets-Sheet 2INVENTOR Lw/.s L. Jco 77? BY MJM ATTORNEY Patented Aug. 30, 1927.

UNITED STATES PATENT OFFICE.

LEWIS I1. SCOTT, OF ST. LOUIS, MISSOURI, ASSIGNOR TO ELEGTROL, INC. OFMISSOURI, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

OIL BURNER.

. Original application filed February 23, 1922, Serial No. 538,559.Divided and this application filed February 3, 1926.

This invention relates to novel apparatus I for use in burning heavyoils which are practically non-volatile at normal temperature, and is adivision of my prior application Serial No. 538,559, filed February23rd, 1922.

The present invent-ion is directed more particularly to the controlsystem illustrated and described in my said prior application, and whilethis invention can be used for many purposes, I have shown it as appliedto a furnace, such as is used for domestic heating. a

One of the objects of this invention is to provide means forautomatically igniting a mixture of oil and air by an electric spark andto provide means for cutting off the electric spark after ignition takesplace. A further object is to provide a means of catching unburned fuel,in case of failure of ignition, and returningsaid fuel to the safetydevice, which is designed to act, under certain conditions, to shut offthe flow of fuel.

The invention is illustrated in the accompanying drawings, in whichFigure 1 is a vertical sectional view of the lower part of a domestichot-air furnace showing my improved oil burner attached thereto; the airpipe and safety float are shown partly in section, said section beingtaken on the line 11 of Figure 2;

Figure 2 is a plan view of the air blower ang connected parts as shownin Figure 1; an

Figure 3 is a diagrammatic drawing showing the complete wiring diagramand control switches. F 7

Referring now to the drawings, the numeral 1 indicates the drum of adomestic furnace; 2 indicates the grate bars commonly used with a coalfired furnace; 3 is the fire door opening; 4 is the fire door of saidfurnace; 5 is the ash door; 6 is an electric motor which drives the fan7 and oil pump 8. -The suction pipe 9 runs to an oil tank (not shown);oil is delivered under pressure through the pipe 10 to the fuel spraynozzle 11. The spray nozzle 11 can be any of the well known pressurespraying fuel nozzles. 12 is a blower housing which delivers lowpressureair through the pipe 13 to the air receiver 14. The casting 15is removably attached to the air receiver 14 and carries the spark plug16 and fuel nozzle 11. The spark plug and nozzle are Serial No. 85,661.

located entirely outside of the furnace proper, and the electric wiresconnected to the former will thus not be subjected to the pipe,preferably curved downward, which is attached to the air receiver 14 andto the furnace 1 and is for the purpose of conducting and directing theburning fuel mixture into the furnace. 20 is a box-like casting havingan open top; said castin rests on the fire bricks 21, which fire bric rsrest on the grate bars 2. The casting 20 serves the purpose of directingthe burning fuel and air, and also serves the purpose of catchingunburned fuel in the event said fuel fails to ignite, and returning saidfuel to the safety chamber 22 through the pipe 23. It will be noted thatthe cast-ing 20 has a raised boss 24: where the pipe 23 connects to saidcasting. The object in using this raised boss 24 is to prevent fuel fromrunning into the pipe 23 when the burner is started from cold and isoperating in the normal way. I have found that when the burner isstarted there is a small amount of wet fuel that will drip out into thecasting 20, which fuel is burned as soon as the burner is operating fora few minutes. If I did not provide this raised boss, the fuel would runinto the pipe 23 and would operate the safety device when there was nooccasion for operating it. 25 is a metal float which is attached to thearm 26, which arm is pivoted at 27. 28 is a rod which is moved upward bythe operation of the float 25 and which acts to break thecircuit to themotorb, thereby stopping the pump 8 (see Figure 3). The operationof theelectric circuit breaker to the motor. will coil 34 of which isconnected to the main line circuit through the wires 33 and 34 35indicates a spark coil Whichis connected to the winding 36 of thetransformer 33 through the wires 35 and 36", the wire 35 being connectedto a wire 47, later referred to. Said spark coil furnishes current tothe spark plug 16. 37 indicates an electric contact which is mounted onthe flat spring 38; 39 is a fiat spring, the end of which is engaged inthe end of the flat spring 40. The 8 )ring 40 is secured to the post 41and bears agaimt the rod 28. The springs 38 and 39 are secured to thepost 42. The contact 37 bears against the contact 43 and forms a switchor circuit breaker in the main line wire 44 so that when said contacts37 and 43 are separated, the main line circuits are broken. 45 indicatesa thermostat which is usually placed in the living room of the house;said thermostat is adapted to move in one direction when the room iscold and in the opposite direction when the temperature in the roomrises. The purpose of the thermostat 45 is to control the operation ofthe motor 6, which motor controls the flow of oil to the furnace,thereby controlling the temperature in the room in which the ther mostatis located. 46 is an electro-magnet which gets its current from the coil36 of the transformer 33 through the wires 47 and 36 The switches 49 and50 are located in the line 36*. The magnet 46 when energized will movethe armature 51 to the i left, as shown in the drawing. The magnet 52gets its current from the same source as magnet 46, but the current tosaid magnet 52 is controlled by the switches 53 and 54. When the magnet52'is energized, it will move the armature to the right. The armature 51is pivoted at 55 and the upper part of said armature contains the ball56, which ball is pressed upward by the spring 57. 58 is a fixed pieceof metal which is located between the arms 59 and 60. The arm 59 ispivoted at 61 and said arm carries the contact 62, which is the switchtoithe motor 6,

and the contact 63, which is the switch for breaking the circuit to themagnet 46. The arm 60 is pivoted at 64, and said arm carries the contact65, which is the switch to the spark coil 35, and the contact 54', whichis the switch for breaking the. circuit to the magnet 52. The numeral 66indicates a piece of thermostatic metal which is fixed at one end to thepost 67, and carries the contact 68 at the opposite end. The contact 68is connected in series with the switch 65 through the wire 69 andthereby controls the operation of the spark coil 35. The post 67 isgrounded through the wire 67 as is the wire 68"-, which is connected toone side of the primary winding of the spark coil 35. The thermostaticmetal 66 is adapted to move upward when heated so as to break thecontact between 68 and 69. 70 is a coil of. wire which is wound aroundthe insulating material 71, which insulating material fits looselyaround the thermostatic metal 66. The coil 7 0 is connected in serieswith the motor 6 by the wires 7 2 and 73. When the motor 6 is started,the current flowing through the coil 70 will heat up the thermostaticmetal 66 and cause same to move upward so as to open the switch 68 andthereby only allow the spark coil 35 to operate for a short period oftime after the motor is started. When the motor is shut oif, thethermostatic metal will cool off and close the switch 68.

I will now describe the general operation of my oil burner. Let usassume that the lire has been burning and the room temperature has beenbrought up to the desired point and that the motor 6 has just been shutoff. As the room temperature drops, the thermostat 45 will move to theright and close the switch 53, thereby sending current through themagnet 52, whereupon the armature 51 will move to the right, therebyallowing the arm 59 to drop downward and moving the arm 60 upward. Asthe arm 59 drops clownward, the switches 62 and 63 close and the motor 6starts. ward, the switch 54 opens, breaking the circuit to the magnet52, and the switch 65 closes, thereby sending current to the spark Asthe arm 60 moves up-- coil 35. The switch 68 will open in a short periodof time, as before described. When the motor 6 starts, fuel is pumped bythe pump 8 and is forced under pressure through the spray nozzle 11. Thefan 7 forces air through the pipe 13 into the air receiver 14, which airreceiver is so formed as to make the air take the path of an involutecurve and to rapidly rotate said air. The funnel-like casting 15 forcesthe air toward the outlet pipe 19. The plate 17 acts to direct the airaround the points of the spark plug 16 and fuel nozzle 11 so that theair velocity at these points is high enough to prevent flame propagationaround the spark plug points and fuel nozzle. Themixture of air and fuelis ignited by the spark plug 16 and the flame of said mixture isdirected into the furnace by the outlet pipe 19.

I am fully aware of the fact that it is not new to ignite a spray of oilby an electric spark and that it is not new to bring in air around saidfuel spray tangential to an air receiver which is located around saidfuel spray. These features are clearly shown in Patent Number 1,207,897, to John Good, dated December 12th, 1916. a

In the event that the fuel should fail to ignite, it will run into thecasting 20 and out through the pipe 23 to the casting 22, whereupon thefloat 25 will move upward, thereby moving the rod 28 and spring 40upward, (see Figure 3). As spring 40 moves upward, it will move out ofengagement with the spring 39 and said spring 39 will move to the left,thereby moving spring 38 and contact 37 to the left so that the mainline circuit to the motor Will be broken and the motor Will stop pumpingoil.

I claim:

1. In an oil burning system, a spray nozzle for spraying oil, means forfurnishing air to promote combustion, an electrically-controlled devicefor supplying fuel to the burner, an electrically-controlled device forigniting the fuel, an electricallyheated thermostat for controlling thetime of operation of the ignition device.

2. In an oil burning system, a spray nozzle for spraying oil, an airblower for furnishing air to promote combustion, a motor for operatingthe blower, an electric device for igniting the fuel, anelectricallyheated thermostat for controlling the time of operation ofthe electric ignition device, and means for turning on or turning ofithe current to the motor and electrically-heated thermostat insubstantial unison.

3. In an oil burning system, a spray nozzle for spraying oil, means forfurnishing air to promote combustion, an electricallycontrolled devicefor supplying fuel to the burner, an electric device for igniting thefuel, an electrically-heated thermostat for controlling the time ofoperation of the ignition device.

4. In an oil burning system, a spray nozzle for spraying oil, means forfurnishing air to promote combustion, an electricallycontrolled devicefor supplying fuel to the burner, an electrically-controlled device forigniting the fuel, an electrically-heated thermostat for making orbreaking the circuit to the electrically-controlled ignition device.

5. In an oil burning system. a spray nozzle for spraying oil, means forfurnishing air to promote combustion, controlled device for supplyingfuel to the burner, an electrically-controlled device for igniting thefuel, an electrically-heated thermostat for making or breaking thecircuit to an electrically thermostat to control the circuit to the sec-0nd transformer, and an electric heater for said thermostat connected tothe feed circuit to cause the thermostat to cut out said ignitingtransformer.

7. In a liquid-fuel burner, the combination of electrically operatedmeans to produce a spray of liquid fuel, a. main feed circuit therefor,an electric transformer to produce sparks to ignite the spray, a feedcircuit for the transformer, an electric heater connected to the mainfeed circuit, and a thermostat adjacent said heater and affected therebyto open the circuit to said ignition transformer when heated.

8. In a liquid-fuel burner, the combination of electrically operatedmeans to produce a spray of liquid fuel, a main feed circuit therefor,an electric transformer to produce sparks to ignite the spray, a feedcircuit for the transformer, an electric heater connected to the mainfeed circuit, and a thermostat adjacent said heater and affected therebyto open the circuit to said ignition transformer when heated, a relay tocontrol the main feed circuit, a second transformer connected into themain feed circuit, a secondary circuit connecting to the secondtransformer and to the relay, and a thermostat connected into the relaycircuit and adapted to open and close the relay circuit and thereby themain circuit.

In testimony whereof, I have hereunto set my hand.

LEWIS L. SCOTT.

